diff --git a/msg_test.go b/msg_test.go
index 8bf0de6..47d5b18 100644
--- a/msg_test.go
+++ b/msg_test.go
@@ -1135,7 +1135,7 @@ func TestMsg_RequestMDN(t *testing.T) {
 	if err := m.RequestMDNTo(v); err != nil {
 		t.Errorf("RequestMDNTo with a single valid address failed: %s", err)
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 1 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 1 {
 		if val[0] != fmt.Sprintf("<%s>", v) {
 			t.Errorf("RequestMDNTo with a single valid address failed. Expected: %s, got: %s", v,
 				val[0])
@@ -1147,13 +1147,13 @@ func TestMsg_RequestMDN(t *testing.T) {
 	if err := m.RequestMDNTo(vl...); err != nil {
 		t.Errorf("RequestMDNTo with a multiple valid address failed: %s", err)
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 0 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 0 {
 		if val[0] != fmt.Sprintf("<%s>", v) {
 			t.Errorf("RequestMDNTo with a multiple valid addresses failed. Expected 0: %s, got 0: %s", v,
 				val[0])
 		}
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 1 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 1 {
 		if val[1] != fmt.Sprintf("<%s>", v2) {
 			t.Errorf("RequestMDNTo with a multiple valid addresses failed. Expected 1: %s, got 1: %s", v2,
 				val[1])
@@ -1174,7 +1174,7 @@ func TestMsg_RequestMDN(t *testing.T) {
 	if err := m.RequestMDNAddTo(v2); err != nil {
 		t.Errorf("RequestMDNAddTo with a valid address failed: %s", err)
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 1 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 1 {
 		if val[1] != fmt.Sprintf("<%s>", v2) {
 			t.Errorf("RequestMDNTo with a multiple valid addresses failed. Expected 1: %s, got 1: %s", v2,
 				val[1])
@@ -1186,7 +1186,7 @@ func TestMsg_RequestMDN(t *testing.T) {
 	if err := m.RequestMDNToFormat(n, v); err != nil {
 		t.Errorf("RequestMDNToFormat with a single valid address failed: %s", err)
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 0 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 0 {
 		if val[0] != fmt.Sprintf(`"%s" <%s>`, n, v) {
 			t.Errorf(`RequestMDNToFormat with a single valid address failed. Expected: "%s" <%s>, got: %s`, n, v,
 				val[0])
@@ -1195,7 +1195,7 @@ func TestMsg_RequestMDN(t *testing.T) {
 	if err := m.RequestMDNAddToFormat(n2, v2); err != nil {
 		t.Errorf("RequestMDNAddToFormat with a valid address failed: %s", err)
 	}
-	if val := m.genHeader[HeaderDispositionNotificationTo]; val != nil && len(val) > 1 {
+	if val := m.genHeader[HeaderDispositionNotificationTo]; len(val) > 1 {
 		if val[1] != fmt.Sprintf(`"%s" <%s>`, n2, v2) {
 			t.Errorf(`RequestMDNAddToFormat with a single valid address failed. Expected: "%s" <%s>, got: %s`, n2, v2,
 				val[1])